The invention relates to a device for playing and storing several disc-shaped data carriers to be operated alternately, in particular CDs, CD-ROMs, and DVDs, with a playback unit designed for playing the data carrier and comprising a base plate and a frame which are coupled to one another by means of springs and/or dampers, and comprising a turntable arranged on the frame and designed for accommodating the data carrier and a pressure device for pressing the data carrier onto the turntable, while a stacking unit is provided for the intermediate storage of several data carriers, and a loading device is provided for the bidirectional transport of the data carrier between the stacking unit and the playback unit as well as for moving the data carrier into and out of the device.
Usually, a stacking unit for accommodating several data carriers, a playback unit on which one of the data carriers can be positioned each time for the purpose of reading or writing of the data, and a loading device for the transport of the data carriers are present in such a device. Given the requirement of a compact construction of the device, the present state of the art is such that the stacking unit stores the individual data carriers one above the other, that the reading or writing operation takes place in one and the same region which lies within the transport range of the data carrier during the selection of the data carrier to be read or written, and that accordingly the playback unit is displaced relative to the stacking unit before the selection of the data carrier to be read or written so as to clear the space for the stacking movement. The present state of the art is furthermore such that the playback unit consists of a base plate and a frame connected thereto by means of springs and dampers, which frame comprises the devices for driving the read/write device and the means for rotating and pressing the data carrier on a turntable. It is also known that the frame is locked with respect to the base plate while the data carrier is laid on or taken from the playback unit by a loading device in a CD player, so that the transfer of the data carrier to the playback unit or to the charging unit (in the reverse operation) is made easier.
It is an object of the present invention to provide a drive for the transport of the playback unit which is inexpensive and simple, and which nevertheless renders possible a fast and accurate positioning and locking of the playback unit in several positions in the device.
According to the invention, this object is achieved in a device for playing and storing several disc-shaped data carriers to be operated alternately, in particular CDs, CD-ROMs, and DVDs, with a playback unit designed for playing the data carrier and comprising a base plate and a frame which are coupled to one another by means of springs and/or dampers, and comprising a turntable designed for accommodating the data carrier and a pressure device for pressing the data carrier onto the turntable, while a stacking unit is provided for the intermediate storage of several data carriers, and a loading device is provided for the bidirectional transport of the data carrier between the stacking unit and the playback unit as well as for moving the data carrier into and out of the device, in that the playback unit is movable by means of a worm gear and can be locked in several positions.
The advantage of the use of the worm gear lies in the exact positioning possibility which can be achieved by means of the slope of the worm gear. In addition, the worm gear is mechanically robust, provides a compact construction, and is capable of transporting several slides simultaneously.
In an embodiment of the invention, the worm gear comprises a continuous thread with several ranges having different thread slopes, suitable for varying the speed of the translatory movements in dependence on the position of the playback unit at a constant worm gear rotation speed, or even stopping said movement completely.
This offers the advantage that the worm gear can always rotate at the same speed, so that an expensive drive providing a variable rotation speed can be dispensed with.
In a further embodiment of the invention, a control slide is displaced by the thread of the worm gear, which slide can be locked to the playback unit, so that the control slide and the playback unit are jointly moved by the thread of the worm gear, and the playback unit itself is retained by interlocking shapes in the device when the locking between the control slide and the playback unit islifted, while the control slide still remains movable on its own and can accordingly be displaced relative to the playback unit, performing switching functions inside the playback unit.
It is possible with this advantageous embodiment for one control slide to suffice both for moving the playback unit and for carrying out further switching functions in the device.
In a further embodiment of the device, the device is provided with a retaining catch for the control slide and the playback unit which is constructed such that it alternately inhibits and releases the movement of the control slide relative to the playback unit or the movement possibility of the playback unit relative to the entire device.
It is safeguarded thereby that the playback unit can only move if the control slide is locked thereto. When the control slide is carrying out switching movements while it is not connected to the playback unit, an undesirable movement of the playback unit is excluded.
It is furthermore provided that the control slide has contours which control the pressure device for the data carrier in the case of a movement relative to the playback unit and which inhibit the movement possibility between the base plate and the frame plate, which is limited by the spring-damper system only, and reduce the distance between the base plate and the frame.
This renders it possible to actuate also the functions of the pressure device by means of the control slide without any further drive such as, for example, a servo drive being necessary for this.
In a further embodiment of the invention, the control slide has a contour which controls the retaining catch in the case of a movement relative to the playback unit.
The control slide can thus advantageously also control the retaining catch, so that a further drive can be dispensed with.
It is in addition provided that the device is provided with a switch for electronic position detection which is integrated in the drive mechanism of the worm gear, or is controlled by the worm gear, or is controlled by the displacement of the control slide.
This offers the advantage that the instantaneous position of the worm gear or the control slide can be made available to the electronic circuits in the device according to the invention by means of an electrical signal.
It is in addition provided that a positioning mechanism is fitted with the features according to the invention as mentioned above.